That is a sweet build. Was looking to build something like that myself but took a dremel to a Cosmos 1000 instead.
Two questions though. What size tubing and fittings did you use? And how secure is the video card? Is the acrylic enough to keep the video card waterblock from touching the motherboard?

Mnemonicman - i started off with an EK-kit H30 360 LT which comes with - TUBE Masterkleer 12,7/9,5 CLEAR and all the relevent fittings too... then i just needed two extra 1/4 pipe fittings for the Heatkiller fx560 block and some elbows to tidy the fit.

The Gpu holds quite nicely against the acrylic layer, with only a small amount of flex in the top one while the build was laying down. the waterbloock is very narrow and theres a gap of 10-20mm between it and the motherboard.
FOr a while i was reaching a finger in to hit the onboard start button!
Theres more than enough room between them to run the 12.7mm OD pipe up between and lay the excess flex cable from the riser card.
Hope this answers your questions!